The present invention relates generally to oil well setting tools of the type adapted for engaging a setting sleeve run on a pipe string into a well bore, and specifically to a setting tool which allows left and right hand torque to be used during well bore operations as well as right hand torque to release the setting tool from the setting sleeve.
Setting tools are used for various purposes during well drilling and completion operations. As an example, a setting tool is typically used during setting of a liner hanger in a well bore. The setting tool is made up as a part of the pipe string between the liner hanger and the pipe string running to the well surface. The setting tool serves as a link to transmit torque to the liner hanger to hang the liner in a well bore. The setting tool is then typically manipulated from the well surface to effect a release of the setting tool from the liner hanger and the liner is then cemented into place in the well bore.
In a typical well drilling pipe string, the lengths of pipe are connected by tool joints with right hand threads which are released by left hand torque. Drilling is thus carried out by clockwise rotation of the drill string to avoid breaking out of the tool joints making up the pipe string. In certain prior setting tool designs, connecting threads were used to engage the setting tool with the setting sleeve which were releasable by right hand torque on the pipe string from the surface. However, this necessitated holding left hand torque on the pipe string while running into the well bore and dictated that the liner be set to the left in order to avoid releasing the setting tool connecting threads. Because left hand torque was used to set the liner, the possibility existed that tool joints in the pipe string would be unscrewed and a joint broken out.
It is, therefore, preferred to utilize a setting tool which allows the liner to be set by applying right hand torque from the surface and which allows the setting tool to be released and pulled out of the well bore by applying a similar right hand torque. There exists a need, therefore, for a setting tool which will allow right hand torque to be used during setting of a liner hanger or similar tool which also allows right hand torque to be used to release the tool.
In certain prior tools, radially moving dogs were used to initially secure the setting tool to the setting sleeve. Vertical manipulation of the pipe string from the surface, accompanied by radial movement of the latching dogs, allowed torque to be transmitted to a setting nut to release the setting tool from the surrounding setting sleeve. The radial movement of the latching dogs presented a possible problem, in that sand and other contaminates could impede their action, causing the tool to malfunction.
In U.S. Pat. No. 4,441,560, issued Apr. 10, 1984 to John L. Baugh et al., a setting tool is shown which allows left and right hand torque for well bore operations and which is releasable by right hand torque. A plurality of fixed torque fingers were received within end notches on the surrounding setting sleeve to transmit torque to the setting sleeve to perform well bore operations. In field practice, operators would sometimes release the setting tool from the setting sleeve and thereafter temporarily set the setting tool back down upon the upper end of the setting sleeve. If the torque finger did not line up axially with the complimentary end notch of the setting sleeve, the torque finger could become damaged, bent or broken, requiring service. A need exists, therefore, for a setting tool with retractable torque fingers to avoid the possibility of damage during temporary weight set-down.
There also exists a need, therefore, for a device of the above type with means for facilitating realignment of the setting tool within the setting sleeve complimentary profile, whereby the setting tool can be reattached to apply further torque to the setting sleeve for further well bore operations.
A need also exists for a device which will allow the setting tool to be used to rotate the liner during the cementing operation without being attached to the liner by the setting nut.
The above described objects are accomplished by an improved setting tool design as will be described in the following written description.